Combined protractor and parallel-ruler.



PATENTED AUG. 4, 190B.

C. J. H. GRANT. COMBINED PROTRACTOB. AND PARALLEL RULBR.

APPLIUATION FILED MAB. l0, 190B.

pv .w n c U am voll-1 slrrozneus PATENT OFFICE.

CHARLES J. H. GRANT, OF CEDAR RAPIDS, IOWA,

COMBINED PROTRAGTOR AND PARALLEL-RULER.

Specification of Letters Patent.

Patented Aug. 4, 1908.

Application tiled March 18, 1908. Serial No. 421,406.

T o all whom 'it may concern:

Be it known that I, CHARLES J. H. GRANT, a citiren of the United States, residing at Cedar Rapids, in the county of Linn and State of Iowa, have invented certain new and useful' Improvements in a Combined Protractor and Parallel-Ruler; and I do declare the following to be a full, clear, and exact de scription of the invention, such as will enable others skilled in the art to which it appertains to make and use the saine.

This invention relates to improvements in combined protractors and parallel rulers.

The object of the invention is to provide a protractor having a stationary and nmovable lade, the latter provided with a series of apertures to receive t-lie point of a pencil, whereby, when the blade is adjusted to various angles, a different number of parallel lines may bc drawn to the inch.

With this and other obiects in view, the invention consists of certain novel features of construction, combination and arrangement of parts as will be described and particularly pointed out in the appended claims.

ln the accompanying drawings, Figure l is a side view of one side of the instrument, showing the manner in which the device is used for drawin parallel lines; Fig. 2 is a movable blade closed upon the stationary blade; Fig. 3 is a longitudinal sectional view on a line with the center of the mov "e blade und Fig. 4 is a vertical cross sectional view through the protractor head on a line with the pivot screw and clamping nut.

ln the embodiment of the invention l provide a irotractor, l, on one corner oi' which is formel a radiallv projection' stationary blade, or ariu, 2, one edge of which is in line with the straight edge of the prot-iactor. The blade, 2, is of somewhat greater thickness than the protract or, and the inner end of the blade pro- ]ects over onto thc rear side of the irotractor and forms u shoulder against whiclli the movable blade of the. prot-ractor is engaged when said blade is in a closed position, as clearly shown in Fig. 2 of the drawing. The inner edge of the binde, 2, is preferably beveled, as shown :it 3.

Arranged in the.I conter oi' the lirotractor is a pivotscrew, 4, on the rear ein of which is secured the inner end of the movable blade, 5, of the instrument, said blade being provided on its1 inner end with a. circular head. 6, and along the length of the blade is formed a sc.-

ries of perforations or apertures, 7, adapted to receive the point of a pencil. On the out-cr side of the protractor is arranged a guide plate, 8, having on its inner end a substantially circular head, 9, irovided with a centrally disposed pivot ho e, l0, which is adapted to be engaged with the outer end oi the pivot screw, 4. The opposite end oi thc plate, 8, adiacent to the outer edge of the protractor, is bent downwardl)` to forni a uide Harige, l2. On the lower edge of the.

ange, l2, is formed a depending stud, 13, which is adapted to be engaged with the. innermost hole in the line of poiforations, 7, thereby holding said guideplate and the movable blade of the protractor in parallel alinement and causing the. plate and the blade to move together. The outer end of the pivot screw, 4, is threaded and on said threaded end is adapted to be screwed a similar clamping nut, i4, which, when screwed down into engagement with the plate. S, will clamp the latter and the inner end of the blade, 5, into tight engagement with the protractor and thereby secure the blade in itsI adjusted positions.

While the device herein shown and described ina be employed as a protractor,

i and for suc i work as an instrument of this similar view of t le reverse side showing the kind is designed to perform, it is primarily intended for use in drawing parallel lines, and, when so used, the stationaryv blade and lower edge of the protractor are a ilplied io a. straight edve and the movable ade, 5, adjusted to he desired position, after which the point of a encil may be engaged with each successive ole, or in any of the holes in said blade, and the instrumentdrawn hack and forth along the straight `edge, whereby inscribing a series of parallel lines, the distances between which may be determined by the angle to which the movable blade is turned, or by placin the pencil in each successive holo, or by s ipping certain numbers of holes, thereby making it possible to draw any number of lines to the inch, and, by turning the straight edges to various positions, the parallel lines may be drawn at dillcrent angles, thus adapting the instrument for use in cross hatching or section-lining, in halltintinv. drawing scre\\'threads, and in many other instances where a number of parallel lines is required to be drawn at diflerent angies.

From the foregoing description, taken in connection with the accompanying drawing,

the construction and operation of the invention will be readily understood Without requiring a more extended explanation.

Various chan esin the form, proportion and the minor dctai s of construction may be re sorted to without departing from the principle or sacricin any of the advantages ot the invention as de ned in the appended claims.

Having described my invention, what I claim as new and desire to secure by Letters- Patent, is:

1. In an instrument of the character described, a protractor havin a stationary blade, a movable blade pivota ly mountedon said protractor, said pivoted blade having formed therein a series of longitudinally disposed aperturef., and means on said r o tractor toguide and hold said pivoted bla( e in its adjusted position, substantially as (lescribed.

2. An instrument of the charactei` described, comprising a protractor having a stationary blade, a combined pivot screw and. clampin nut, a movable blade ivotally mounts on said screw, said blade aving a series of apertures, and a combined guiding and holding plate secured by said screw an nut and ada ted to guide and hold said movable blade in its adjusted position on the protractor.

3. A combined protraetor and parallel ruler, comprising a protractor having a stationary, radially projecting blade, a movable blade ivotally mounted on said protractor, and a apted to be 4moved into am out of cngagement with said stationary blade, a guide plate to engage the opposite side of the protractor from said movable blade, a guide flange on the outer end of said late, a stud on said flange to engage one of tie apertures in said blade, and means to clamp said guide plate and movable arm in their adjusted positions on the protractor, substantially as de scribed.

4. A combined protractor and parallel ruler, comprising a protractor having a stationary, radially projecting blade, a movable blade fpivotally mounted on said rot-rector, and a apted to be moved into an( out of engagement with said stationary blade, a guide plete to engage the opposite side of the protractor from said movable blade, a guido flange on the outer end of said plate, a stud on said flange to engage one of the apertures in said blade, and a clamping screw and nut ada ted to be screwed into engagement with sai guide plat-e to hold the same and said movable blade in their adjusted iositions on the protractor, substantially as escrbed.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

CHARLES J. H. GRANT. Witnesses:

WiLLIAM B. SMITH, Giro. B. CHAMBERLIN. 

